Time right to increase garden shrubs for free

Dahlia tubers stored in large pot (S)
Dahlia tubers stored in large pot (S)

How to take hardwood cuttings from shrubs and fruit bushes this week by Martin Fish - Show director, Harrogate Flower Shows

This week I want to look at hardwood cuttings of deciduous shrubs.

These are taken in November and December and as the name suggests, hardwood cuttings are taken from woody stems of this year’s growth that have ripened over the summer and autumn. To prepare a cutting, select a strong, healthy stem and using secateurs trim the base just below a leaf joint (node) and make a sloping cut just above a node at the top of the cuttings. The length of the cutting will vary depending on shrub, but as a general rule hardwood cuttings should be between 20-30cm (8-12 inches) long.

Once the cuttings have all been prepared, traditionally they would have been inserted into the soil outside, by pushing the cutting two-thirds its length into the soil, approximately 15cm (six inches) apart. In spring the buds at the top of the cuttings would start to grow and by autumn a new plant would have developed. However, in the garden at home where you only want a few new plants, another very simple method it to insert the cuttings into deep cell trays or pots filled with multipurpose compost. Over winter keep the cuttings in a cold frame or cool greenhouse and when roots and new growth is established next spring, the rooted cuttings can be potted into larger pots and grown on for a season.

The type of shrubs you can easily propagate this way include the lovely coloured stemmed willows and dogwood, forsythia, flowering-currant, philadelphus, deutzia, weigela and buddleia, plus fruit bushes such as black, red and white currants and gooseberries.

Readers’ Questions

Maria has just dug up her dahlia tubers and she has emailed me to ask what is the best way to over-winter them.

The main thing with dahlia tubers is to protect them from frost. It is also important to make sure that the fleshy roots do not dry out too much over the winter months.

Once I have lifted my dahlia tubers, I cut the stems down to a few inches above the roots and leave them for a few days on their side to dry off a little. Any damaged roots are snipped off and I then place the tubers into pots and partly cover them with damp compost which keeps the roots hydrated. Through the winter the pots are kept under the bench in my greenhouse where the temperature is frost-free.Alternatively a garage or insulated shed will be fine.

Jobs for the week

Check hyacinth bulbs that are being grown for Christmas. At this stage they should have short green foliage with flower buds developing in the centre of the leaves. Grow the bulbs on in a light, cool place.

Choose a dry, sunny day and give your lawn a final light trim of the season to keep it looking tidy over winter.

In frosty weather make sure that outside taps are well insulated, or better still turned off at a stop-cock to prevent frozen pipes.